Experts warn that battle-hardened ISIS fighters are travelling among refugees from Syria over land and using human trafficking routes to slip back into the UK undetected - where they could launch attacks.

Denis Pushlin, the head of the self-declared Donetsk People's Republic, said he did not consider his men to be bound by the peace deal brokered by the U.S., Russia, Ukraine and Europe in Geneva on Thursday.

Officials warned the 56 athletes and 64 other members of Team GB to keep a low profile while in the country for the showpiece Games in Sochi, particularly while travelling through the capital city Moscow.

At least 47 women and children, including two three year-olds, have been executed by militia loyal to Syrian President Bashar Assad and the death toll is expected to rise, activists claimed last night.

The murder of Ghulam Haider Hamidi, a close ally of beleaguered President Hamid Karzai, raised further disturbing questions about Afghanistan’s transition process with responsibility for security being transferred from British, US and other Western troops to Afghan forces.